A currency can only be stable if its future existence is not in doubt,” said Jörg Asmussen, the powerful German member of the ECB’s executive board.

He signalled full backing for the bond rescue plan of ECB chief Mario Draghi, brushing aside warnings from the German Bundesbank that large-scale purchases would amount to debt monetisation and a back-door fiscal rescue of insolvent states in breach of EU treaty law.

Mr Asmussen told the Frankfurter Rundschau that the surge in Club Med bond yields over recent months “reflects fears about the reversibility of the euro, and thus a currency exchange risk” rather than bad economic policies in struggling states.

A d v e r t i s e m e n t

The choice of wording is crucial. If it can be shown that the ECB is acting to avert EMU break-up – known as “convertibility risk” – bond purchases would no longer be deemed a bail-out for Italy and Spain.